<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      div {
        width: 300px;
        height: 300px;
        border: 1px solid #000;
        margin: 50px auto;
        position: relative;
      }
      img {
        position: absolute;
        top: 50%;
        left: 50%;
        animation: tobig 3s linear infinite;
        transform: translate(-50%, -50%) scale(0.2);
        opacity: 0;
      }
      img:nth-child(2) {
        animation: tobig 3s 1s linear infinite;
      }
      img:nth-child(3) {
        animation: tobig 3s 2s linear infinite;
      }

      @keyframes tobig {
        0% {
          transform: translate(-50%, -50%) scale(0.2);
          opacity: 0;
        }
        50% {
          transform: translate(-50%, -50%) scale(1);
          opacity: 1;
        }
        100% {
          transform: translate(-50%, -50%) scale(2);
          opacity: 0;
        }
      }
    </style>
  </head>
  <body>
    <div>
      <img src="./images/hua2.png" alt="" />
      <img src="./images/hua2.png" alt="" />
      <img src="./images/hua2.png" alt="" />
    </div>
  </body>
</html>
